Roads to node-where

Lines illustrate the physical infrastructure that connects the internet across the United States.

Internet users may soon notice a boost in performance thanks to a team of UW-Madison researchers who published an atlas of its physical structure around the world.

“It’s the most accurate representation of the internet’s physical structure in 24 years,” says graduate student Ram Durairajan. “There are so many questions around cyber-security and this will help service providers address these concerns.”

About a dozen people at UW-Madison worked on the Department of Homeland Security-funded atlas over the five years it took to complete. Although previous attempts to map the internet’s physical structure have been made, this is the most comprehensive and accurate.

The physical internet includes hosting facilities and data centers, known as nodes, the conduits and links that connect nodes, and relevant meta-data, Durairajan explains.

Durairajan says the atlas will help reduce service providers’ shared risk, a concept that has as much to do with cost as it does performance.

Physical infrastructure is commonly shared by multiple providers, so damage to any one piece of infrastructure can impact multiple companies and millions of users.

Multiple service providers, for example, may share the cables buried beneath the ocean floor to spread the expense.

“Those cables provide the critical infrastructure across continents,” Durairajan says. “But I could go scuba-diving and cut those cables.”

For example, the April 2011 Miyagi earthquake in Japan caused major disruptions to internet connectivity.

One solution being explored by researchers at the University of Rochester is a high-speed emergency internet to re-establish connectivity when failures occur during natural disasters and other large-scale emergencies.

The UW team mapped out the internet’s physical structure using publicly available data found on the websites of internet service providers.

While the atlas is the most accurate and comprehensive to date, it isn’t exhaustive. Only data from the world’s top 20 providers was used to create the atlas. There are areas around the world, like the American Southwest, that are big open spaces in the atlas.

“That’s either because there is no internet connectivity in those areas or the providers in those areas weren’t captured by our study,” he says.

The internet is not as ubiquitous as it may feel to some. An estimated 57 percent of the world’s population — or 4.2 billion people — don’t have access. There are many places that remain unconnected.

“If you look at the map we constructed, in the Rocky Mountains region, you can’t run wires through mountains so they must follow along the right-of-way,” Durairajan says.

The atlas might not be rocket science, but it took a lot of grunt work. By 2014, according to a presentation by UW-Madison computer science professor Paul Barford, the project had identified 13,734 nodes in 7,932 unique locations across 372 networks.

“This information is very useful,” Durairajan says. “But it isn’t what most people think about when using the internet.”